It has long been known that the long-term use of absorbent articles such as nappies for children and adults can give rise to skin irritation of various types. Skin irritation may originate in chafing on account of mechanical action, or moisture-related problems of various types as a result of the skin of a wearer coming into contact with a moist surface of the absorbent article, or the skin of a wearer coming into contact with bowel movements present in the nappy. In this context, bowel movements or movements mean feces.
As far as bowel movements are concerned, the problem of skin irritation arises especially when movements are mixed with urine, because such a mixture starts known reactions comprising inter alia ammonia, enzymes and a large quantity of bacteria. The mixture of movements and urine moreover affects the skin of a wearer to an especially great extent when the skin is damaged or affected in some other way, for example by chafing or other mechanical action.
The interaction of several factors leads to the development of nappy dermatitis. Moist skin means that chafing and pressure rubs the skin more readily. A higher moisture content also means that penetration of the skin by irritating substances can increase, and also that bacteria and fungi thrive to a greater extent. Occlusion of the skin and the breakdown of the urea in urine into ammonia results in the pH being increased. The higher pH value leads to enzymes (lipases and proteases) originating from the intestine and from microorganisms in the movements being able to break down the skin. This can easily become a vicious circle in which various factors facilitate and intensify one another.
The best way of avoiding dermatitis occurring is by creating circumstances which counteract the factors which create and support the nappy dermatitis process. It is desirable for a wearer to keep the skin as dry as possible, to air the skin frequently and to change wet nappies. Mechanical shear forces should be minimized by choosing materials which are as smooth and soft as possible, and reducing rubbing between the nappy and the skin. By applying a softening protective lotion or cream to the skin, it is also possible to strengthen the barrier against penetration by irritating substances and enzymes. In more serious cases of dermatitis, microorganisms may have infected the damaged skin, and treatment with more active medicaments is required. Use is then made of ointments containing cortisone and various fungicidal and bactericidal agents.
Various ways of solving the abovementioned problems associated with an absorbent article which receives movements and urine have been proposed, inter alia by using various arrangements such as inserts for separating movements from urine, or by using different materials or inserts for transporting liquid away from the interface between the skin and the absorbent article.
WO 99/60975 discloses an absorbent article comprising an arrangement with fairly non-compressible spacer elements which form a zone within which movements are intended to be collected. The non-compressible spacer elements can keep some of the movements present in the zone away from the skin of a wearer, but simply providing a zone in the form of an open “box” allows the movements present in the zone to move freely without any control whatsoever. This results in, for example, the possibility of movements, especially loose movements, moving within the zone in such a manner that they accumulate locally within the zone in such an amount that they come into contact with the skin of a wearer. Furthermore, loose movements can move in the zone on account of the movements of a wearer in such a manner that they can “splash” against the skin of the wearer.
WO 99/07317 discloses an absorbent article comprising an arrangement which swells on contact with liquid and forms a container for movements. One problem of such an arrangement is that it makes great demands of the material in the swelling body and that the functioning of the arrangement depends on it being exposed to a sufficient amount of moisture. Furthermore, the arrangement leads to the same functional problems as WO 99/60975.
WO 98/17219 discloses an absorbent article comprising a fixed arrangement for collecting movements. The arrangement includes a ring made of an elastically compressible material arranged in a central part of the absorbent article. The arrangement is equipped with channels along the perimeter of the arrangement, which allow liquid to migrate out from the area bounded by the arrangement. An arrangement comprising too compressible a material results in problems of the arrangement keeping its shape, and moreover said channels allow a certain amount of liquid movements to run out of the arrangement and thus spread over parts of the nappy which come into contact with the skin.
EP 1064898 discloses an absorbent article, or insert, intended to deal with both urine and movements. The article is constructed from an upper layer with a number of holes, which upper layer is located above a retaining layer for movements, which retaining layer is located above a liquid/moisture-absorbing layer. The retaining layer has a structure with a number of cavities.
The absorbent article has elastically deformable leakage barriers which are intended to fit tightly against the skin of a wearer in order to eliminate side leakage and which surround and define a region where urine and waste products are intended to come to lie. The leakage barriers also define the outer edges of the absorbent article. The various layers mentioned above are located in the region defined by the leakage barriers and against an inner side of the leakage barriers.
The liquid/moisture-absorbing layer is located against the retaining layer in such a manner that a gap arises between the two layers.
The purpose of the gap is that the movements which pass through the retaining layer via the cavities are to be retained in the space defined by the gap.
According to EP 1064898, the cavities have a size which is the same as or larger than the holes which have a size of 20-500 mm2, which means that the majority of the movements pass through the retaining layer to the cavity constituted by the gap.
The EP 1064898 arrangement intended to retain movements is unnecessarily complicated, and the space constituted by the gap can be compressed. The possibility of storing movements is therefore limited. Moreover, the leakage barriers are elastically deformable in such a manner that the possibility exists of the skin of a wearer coming into contact with any movements which have not been transported away from the upper layer.
A desire remains to obtain an absorbent article with an improved capacity for keeping the skin of a wearer free from contact with movements so as to reduce the problem of skin irritation which arises as a result of contact between the skin and the movements/urine.
The previously known absorbent articles which do not separate movements from urine still allow contact between movements present in the absorbent article and the skin of a wearer, which involves a risk of skin irritation. Such articles are characterized by only having good transport of liquid away from the interface between the skin and the absorbent article for the purpose of creating a dry surface of that part of the absorbent article which faces the wearer.
A desire therefore exists to solve the problem with an absorbent article which allows movements and urine to be received but which lessens or completely reduces the contact between the skin and movements when the absorbent article is used.